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Bryan Lawrence edited this page Mar 20, 2016 · 8 revisions

Draft CMIP6 DRS Specification

The DRS effectively consists of the components necessary to identify the properties of an atomic dataset (and to support navigation to, and aggregation of, the atomic datasets).

It consists of three notional components (the parenthetical terms in the following are illustrative and not suggested to be normative in any way):

  • An experimental definition piece
    • What experiment was a simulation run for (project, mip, experiment)
  • A simulation response piece
    • Details about the simulation (institute, model, ripf)
  • Variable pieces
    • Properties of the variable stored in the atomic dataset (frequency, variable_name, table_id, geographical or temporal subsetting, etc )

Historical Material

Existing Views of DRS as rendered in ESGF facetted browse

Permitted Characters

(from CMIP5 DRS spec): The character set permitted in the components needs to be restricted in order that strings formed by concatenating components can be parsed. For the purposes of this scoping exercise, it will be assumed that the components will be used in URLs, punctuated by “/”, “=”, “:”, and “?”, and in the names of files delivered to users, punctuated by “.” and “_”. Thus, none of these characters can be permitted within the component values. Other characters will also be excluded at this time, so the permitted characters will be: a-z, A-Z, 0-9, and “-”. In constructing the “variable name” component of the DRS, it is recommended that the “-“ be avoided since hyphens cannot be imbedded in Fortran and IDL variable names, and some users would like to maintain consistency between the DRS name and the name appearing in their code.

CMIP5 DRS for comparison

Atomic datasets are defined by

 activity
 product
 institute
 model
 experiment
 data sampling frequency
 modeling realm
 variable name
 MIP table
 ensemble member
 version number

with optional extra suffix facets:

 time/period
 geographical subsets and spatial means

With files named as filename = <variable name>_<MIP table>_<model>_<experiment>_ <ensemble member>[_<temporal subset>][_<geographical info>].nc

SPECS DRS for comparison

CORDEX DRS for comparison